1. Field of the Invention
This invention relates to novel lubricant compositions.
2. Description of the Prior Art
Heretofore, various lubricants have widely been used for the prevention or reduction of friction or wear in bearings of machines and the like. Lately, the use of lubricants is of particular interest in view of resource-saving and energy-saving.
These lubricants are classified into a lubricating oil, a grease, a solid lubricant and others in view of their forms. Since there are many fields of application, lubricants are used under various conditions which range from moderate conditions of low load, low speed and the like to very severe conditions of high load, impact load, high speed and the like. Into lubricants are usually compounded various additives so as to be usable under various conditions as described above.
The proper selection of lubricants is an important factor in the lubricating art, which greatly influences the smooth operation and life of machines.
In the development of excellent lubricants, it is ideal to develop all-purpose lubricants. However, since lubricants are used under the various conditions mentioned above, it is impossible to apply a single lubricant to all purposes, so that it is presently attempted to extend the fields of application of a single lubricant as far as possible. In order to develop or produce a lubricant suitable for certain purposes, it is important to precisely grasp the states and conditions encountered to select a lubricant form and additives adaptable therefor. The lubricant form is relatively easily determined because the selection thereof is frequently restricted by the mechanisms and circumstances of the lubricating areas of the machines and installations involved. On the other hand, the selection of proper additives is not easily determined because the additives are numerous and it is difficult to predict how additives act on the lubricating area of the machines and installations involved. Therefore, proper additives are generally selected by a simulation test for the lubricating areas involved. In general, additives for lubricants are classified into an oiliness agent, an extreme pressure agent, an antiwear agent, an antioxidant, a rust inhibitor, a corrosion inhibitor, a dispersant, a pour point depressant, a viscosity index improver, an emulsifier, a defoamer, an antifungal agent and the like. A great number of additives have been developed and used in the form of liquids and solids. Among them, certain additives may possess two-purpose function as a combination of extreme pressure agent and antioxidant, pour point depressant and viscosity index improver, emulsifier and rust inhibitor, or the like. Furthermore, some extreme pressure agents, antiwear agents and the like are added as a dispersion because they are insoluble in a lubricating oil or the like.